Networking: why RepNotify Attributes when you can replicate movement and skills ID only?

I am pretty sure if the system was not done properly and was bad network performance wise, Epic would have changed it or fixed it, and not use it in a 100 player battle royale game. And attributes like all properties will only replicate when they have been changed. So if you don’t change them they will not replicate. You only pay bandwidth when you are modifying the attributes.